Colostrum Extracellular Vesicle Isolation, Characterization, and Function.

Background: Colostrum extracellular vesicles (C-EVs) are nanoscale, bioactive vesicles with therapeutic potential. The mechanisms of action include the control of cellular and tissue homeostasis. These make C-EVs a novel means to control inflammatory and cellular dysfunctions. However, a limitation for their broad use is the ease of C-EV isolation and in ensuring their stability. Methods: Standard ultracentrifugation and gradient techniques used for EV recovery were employed, which included ultracentrifugation. Exodus dual-frequency ultrasonic nanofiltration (UNF) was a comparator used to overcome standard limitations by recovering pure vesicles at high concentrations. Both systems were evaluated for their abilities to recover clinical-grade C-EVs with optimal vesicle structural integrity and intact biological functions. Results: This study affirms UNF C-EV recovery by demonstrating intact Alix, CD63, Tsg101, and Flotillin antigens. The EVs maintained an intact bilayer structure with sizes ranging from to 50-200 nm. Functional tests showed preservation of their anti-inflammatory activities by suppression of pro-inflammatory cytokines and the NLRP3 inflammasome, caspase 1, interleukin-1, and 18 and maintaining cellular homeostasis. Processing time, high yield, and functional responses controlled cellular function. Conclusions: These data support the notion that UNF C-EVs can be recovered safely, at high yields, and reproducibly for future clinical applications.